Internal combustion automobile engines typically require a separate electric motor, or starter, to externally rotate the engine crankshaft at a sufficiently rapid rate to start the engine. The starter is electrically powered by an automobile battery. It is important that the automobile battery have sufficient power to rotate the starter fast enough that it effects starting of the engine. However, occasionally an automobile battery may inadvertently become partially depleted or discharged, such as due to the lights or radio of the automobile being left on without the car running. Typical automobile batteries have a voltage potential of approximately 12V. While even depleted automobile batteries retain a potential of greater than 10V, this depleted battery charge may be insufficient to drive the starter with enough electrical power to crank the engine, resulting in the inability to start the engine. Accordingly, it is known to electrically connect a separate booster battery to the automobile battery to provide the requisite 12V potential for starting the engine. The booster battery is connected in parallel to the depleted automobile battery through electrical cables in order to recharge or bypass the depleted automobile battery. This is commonly referred to as "jump starting" the depleted automobile battery.
Typically, a pair of electrical cables commonly referred to as "jumper cables" are employed which have clamps adjacent either end of each cable. The clamps at either end of one cable are connected to respective negative terminals of the automobile battery and booster battery, and the clamps at either end of the other cable are connected to respective positive terminals of the automobile battery and booster battery. This requires that four separate electrical connections be made, and if any one or more of the connections is made poorly or improperly, it may result in short circuiting and/or failure to start the engine. Additionally, after one end of a cable is clamped to its respective battery terminal, the cable, including the clamp at the other end of the cable, is live, and hence great care must be exercised in handling of the live cable and clamp, and in preventing contact between the positive and negative cables.
Some manufacturers have combined the booster battery and cables in one unit, with one end of each of a pair of cables permanently connected to respective positive and negative terminals of the booster battery. A particular problem associated with this structure is that cables which are permanently connected to the battery are always live. Hence, care must be exercised at all times in the handling of the clamps. Clamp shielding structures, such as holsters molded on the housing in which the clamps are receivable to shield the clamps from one another, and from contact with persons during transporting of the booster battery, have been employed. However, this does not provide any protection to users with regard to exposure of the clamps having live voltage during usage of the booster battery, i.e. during the time the clamps are removed from their holsters and connected to the automobile battery, as well as during the time the clamps are subsequently removed from the automobile battery and returned to their holsters. Accordingly, there remains a need for a booster battery which overcomes the aforementioned problems associated with handling live clamps during jump starting of an automobile engine.